Heat exchanger



Oct. 28, 1958 R, MlLLER 2,858,113

HEAT EXCHANGER Filed Oct. 14, 1954 3 Sheets-Sheet l J. R. MILLER HEATEXCHANGER Oct. 28, 1958 5 Sheets-Sheet 2 Filed Oct. 14. 1954 ASF T IIIwm @L1 w Oct. 28, 1958 FiledOct. 14, 1954 J. R. MILLER 2,858,113

HEAT EXCHANGER 3 Shets-Sheet 3 United States Patent (if)V HEAT EXCHANGER John R. Miller, West Hartford,

Aircraft Corporation, tion of Delaware Conn., assignor to United EastHartford, Conn., a corpora- This invention relates to a surface typeheat exchanger for the transfer of heat from one lluid to anotherthrough intervening surfaces.

An object of this invention is to provide a heat exchanger which isideally suited for use within a circular duct.

Another object of this invention is to provide a heat exchanger whichwill withstand very high pressures, or variations thereof to lowpressures.

A further object of this invention is to provide a heat exchanger havinga large heat transfer surface per unit volume of space occupied.

Another object of this invention is to provide a heat exchanger havingincorporated therein a leak receiver and detector.

Further Aobjects and advantages will be apparent from the followingspecication and drawing:

Fig. l is a side view of the heat exchanger partially in section With `aportion in the center removed. t

Fig. 2 is a view taken along the line 2 2 of Fig. l showing the top halfof the heat exchanger with a portion of the inlet header removed to showthe connection of the tluid flow tubes to the inlet header extensions.

Fig. 3 is a View showing a section of an inlet header extension withseveral inlet header extension adapters connected thereto. t

Fig. 4 is a sectional view taken through a portion of a line of tluidflow tubes.

Fig. 5 is a perspective view of a portion of a leak detection duct.

Fig. 6 is a View of the center section of the heat eX- changer takenalong line 6 6 of Fig. 1.

Fig. 7 is an enlarged view of an inlet header extension adapter.

Referring to the figures, in Figs. 1 and 2, this heat exchanger 1 isshown as being of a one-pass and crossow arrangement, and comprises amain gas flow duct or chamber 2 and a liuid header system 3. The gasilow duct or chamber 2 has a circular outer casing 4 with its forwardend having a circular flange 5 fixed thereto 'and with its rearward endslideably mounted in a duct member 6. Circular flange 5 may be xed toany inlet device desired and duct member 6 may be xed to any exhaustdevice desired.

The lluid header system 3 has a main inlet header 7 and a main outletheader 12. The main inlet header 7 passes through an opening 8 in theouter casing 4 of the gas flow duct or chamber 2 of the heat exchanger 1and extends radially to a point near the center A of the duct.

A plurality of inlet header extensions 9 extend lengthwise in a radialplane within the casing of the heat exchanger from a point adjacent tothe main inlet header 7. Said radial plane extends through the maininlet header 7.

In the heat exchanger shown in the drawings, six of these inlet headerextensions are incorporated. To further identify a specific inlet headerextension the general reference numeral 9 has added thereto the lettersa through f. The reference numeral 9a is applied to the inlet headerPatented Oct. 28, 1958 extension located adjacent the outer casing 4,and the remaining numerals 9b, 9c, 9d, 9e and 9j are applied to eachinlet header extension, respectively, as it is located progressively intoward the center A of the heat exchanger. While six inlet headerextensions 9 have been shown it is to be understood that any otherdesirable number may be used.

Inlet header adapters 10 connect the main inlet header 7 to the inletheader extensions 9. Each inlet header adapter 10 connects two inletheader extensions 9 to the main inlet header 7. An inlet header adapter10 is a unit comprising an inlet pipe 14 connected to two outlet pipes16. As viewed in Fig. l, inlet pipe 14 of each inlet header adapter 10is fixed to the inlet header 7 with the outlet pipes 16 of each inletheader adapter extending rearwardly, one over the other in a radialline. Outlet, pipes 16 are fixed, one each to the forward end of anainlet header extension 9.

Three Vof these inlet header adapters 10 are incorpo-- rated in the heatexchanger shown in the drawings. Inlet, header adapter 10a connectsinlet header extensions 9a'4 and `9b to the main inlet header 7, inletheader adapter 10b connects inlet header extensions 9c and 9d to themain inlet header 7, inlet header adapter 10c connects inlet headerextensions 9e and 9f to the main inlet header 7.

A main outlet header 12 passes through an opening 18 in the outer casing4 of the gas flow duct or chamber 2 of the heat exchanger 1 and extendsradially to `a point near `the center A of the duct. Opening 8, referredto above, and opening 18 are located in the circular outer casing 4 latpoints which are diametrically opposed. Further, main inlet header 7 andmain outlet header 12 lie in a diametrical plane passing through the twosaid openings, 8 and 18. A plurality of outlet header extensions 20extend lengthwise in a radial plane within the casing of the heatexchanger from a point adjacent to the main outlet header 12. Saidradial plane extends through the main outlet header 12.

In the heat exchanger shown in the drawings six of these outlet headerextensions are incorporated. T o further identify a specic outlet headerextension the general reference numeral 20 has added thereto the lettersa' through f. The reference numeral 20a is applied to the: outlet headerextensions located adjacent the outer casting:y 4 and the remainingnumerals 20h, 20c, 20d, 20e, andi 20]c are applied to each outlet headerextension, respec tively, as it is located progressively in toward thecenter A of the heat exchanger. While six outlet header extensions 20have been shown, it is to be understood that any other desirable numbermay be used.

Outlet header adapters 22 connect the main outlet header 12 to theoutlet header extensions 20. Each outlet header adapter 22 connects twooutlet header extensions 20 to the main outlet header 12. An outletheader adapter 22 is a unit comprising two inlet pipes 24 connected toone outlet pipe 26. As viewed in Fig. l, outlet pipe 26 of each outletheader adapter 22 is xed to the outlet `header 12 with the inlet pipes24 of each outlet header adapter extending rearwardly, one over theother in a radial line. Inlet pipes 24 are fixed, one each to theforward end of an outlet header extension 2l).

Three of these outlet header adapters 22 are incorporated in the heatexchanger shown in the drawings. Outlet header adapter 22a connectsoutlet header extensions 20a and 2llb to the main outlet header 12,outlet header adapter 22b connects outlet header extensions 20c and 20dto the main outlet header 12, and outlet header let headerextension 20.vA plurality of header extension..

3 adapters 28 are fixed along the length of each inlet and outletextension 9 and 20 on each side thereof. The header extension adapters28 difer slightly for each inlet and outlet header extensions 9 and 20,which are not Y connected together. The header extension adapters 28 foreach inlet and outlet header extension connected together are the same.To. identify a specific inlet and outlet extension adapter ythe generalreference numeral 28 has added theretoone of the letters a through f.

As noted in Fig. 6, the slight difference between each header extensionadapter 28 is in the length of the adapter which is caused by the`change in angle between the adapter and the extension to which it isconnected. A header extension adapter is a unit comprising a single pipe38 connecte-d to two. smaller pipes 32. This is clearly shown in Fig. 3,in which three adapters 28 are shown attached to an inlet headerextension 9. Each outwardly extendingpipe 32 of the inlet headerextension adapters is connected `by a fluid flow tube 40y to` itsrespective pipe 32 of theV outlet header extension adapters. These fluidow tubes are formed so that they lie along an arc` f a circle betweenthe adapters. This provides an arcuate bank of fluid iiow tubesextending from the header extension adapters on each side of each headerextension 9 to the header extension adapters on each side of the headerextensions 20. Said tubesin each bank are positioned together, eachsuccessive tubeA abutting the preceding tube. To identify a specific uidow tube the general reference numeral 40 has added thereto one of theletters a through f. For example, a uid flow tube connecting an inletheader extension adapter 28a to an outlet header extension adapter 28ais given the reference numeral 40a and a fluid ow tube connecting anVinlet header extension adapter 2811 to an outlet header extension`adapter 28b is given the reference numeral 40b. While these fluid flowtubes 40 may be connected to their respective header extension adaptersby any means desired, the outwardly extending ends of pipes 32 of theadapters are providedv with an inwardly tapered bevel to receive anoutwardly tapered bevel at the end ofthe fluid flow tubes. Thisconnection is then xed by known means such as brazing or welding.

Each header extension adapter 28 has formed integrally therewith twobosses 44. One boss extends between the pipes 32 on one side of theadapter 28 and `another boss extends between the pipes 32 on the otherside. Each boss extends approximately the length of the pipes 32 and hasa width which extends from the center of one pipe 32 tothe center of theother integral pipe 32. Each boss presents a face 52 lying in a planewith the ends of pipes 32. A groove 48 extends the full width ofl eachboss. A passageway 50 extends from the face 52 of each boss to thebottom of its groove 48. The passageway 50 as it intersects the face 52of the boss is triangular in shape as at 54 and has an inwardly beveledface 56 for a reason to be hereinafter described. The passageway 50 asit intersects the bottom of groove 48 forms an aperture 58.

As viewed in Fig. 3 it can be seen that the header extension adaptersare connected to a header extension so that the pipes 32 of adjacentadapters abut one another. All of the header extension adapters aremounted in this manner. When these adapters are iirst mounted they givean appearance between them as indicated to the right of Fig. 3 by theletter B.

In the construction of this :heat exchanger Vit isl desired that thespace between the adjacent pipes 32, not integrally attached, and bosses44 attached thereto, be built up to appear similar to a boss 44. This isdone by the use of an insert 144 which is placed between the adjacentpipes 32 and their respective bosses 44. This insert 144 is curved as at60 to have a snug fit with the exterior portions of pipes 32 and isofsuch a width so that it ts snugly between the ends of adjacent bosses44. As viewed in Fig. 3 this insert has a groove 148 which ex tends thefull width of the insert. A passageway 150 extends from the face 152 ofthe insert to the bottom of the groove 14S. The passageway 150 as itintersects the face 152 of the insert is triangular in shape as at 154and has an inwardly beveled face 156 for a reason to be hereinafterdescribed. The passageway 150 as it intersects the bottom of groove 148forms an aperture 158,. The insert is shown inthis position to the leftof Fig. 3 where it has been aixed by any means desired. The insert isused on both sides of each adapter. While the boss 44 has been shown asintegral, it is to be understood that it can also be made as insert 144.

A completed line of header extension adapters 2-8 and inserts 144 alongan extension presents a long groove extending from the first tube to thelast on both sides of the adapters. These grooves have a series of holes58, 158 in the bottom thereof extending from one end to the other. Thetriangular openings at 54 and 154 have an outer edge of the beveled-face 56 located in a line with the top or bottom of each of the pipes32. Each triangular opening' on bosses 44 or inserts 144 of the inletheader extension adapters is connected by a leak detection duct 62,having a triangular shaped cross section, to its respective triangularopening on bosses 44 or inserts 144 of the outlet header extensionadapters.

Each leak detection duct 62 contains metallic bers. These may be ofmetals such as silver or c-opper. This provides for heat transferthrough the duct and for uid flow along the duct. While these leakdetection ducts 62 may be connected to their respective bosses orinserts by any means desiredthe triangular openings at 54' are providedwith an inwardly tapered bevel to receive the outwardly tapered bevel atthe end of the leak detection ducts. This connection is then xed byknown means suchl as brazing or welding. These leak detection ducts 62are formed so that they lie along an arc of a circle between adjacentfluid ow tubes 40. The side 70 ofthe `leak detection ducts abutting thebeveled edge of `holes 50 and 150 whichl are aligned with the edges ofpipes 32 is solid, the other two sides 72 which extend down into theV-shaped channel formed by adjacent fluid ow tubes 40 have sl-ots 76extending for a distance less than the I width of the sides (see Fig.5).

A collection tube is fixed in each long groove extending al-ong acompleted line of header extension adapters 28 and inserts 144 and hasholes 82 therein, one each which cooperates with each of the holes 58,158 in the groove. These tubes 80 are closed at their rearwardlyextending end and are all attached at their forwardly extending end totwo main collector tubes 86. These tubes 86 extend one along each sideof the main inlet header 7 and main outlet header 12 from the top to thebottom of. the heat exchanger. The ends of tubes 86 are connected to aleak detection and receiver means 90. This means may be of anyconstruction depending on the fluid to be received and detected.

A shell 64 is placed on each side of each arcuate bank of tubes. Tolidentify a specific shell the general reference numeral 64 has addedthereto one of the letters a through f. For example, the shell on eachside of the bank of tubes 40aisl given the reference ,numeral 64a. Itcan be seen that the various shells 64 will vary in length and arcuateshape depending on which bank of tubes they are placed and on which sideof that bank. This is evident from Fig. 2 `of the drawings. The shells64 extend in length from the first tube in the bank to the last. Theupper and lower ends 66 of each shell' abut the` portion of faces 52 and152 which are located between a line i extend lengthwise along the openside of each shell 64. These iins 102 may be formed integral with theshell.

The header extensions 9 and 20 are mounted in the casing 4 of the heatexchanger in the following mnaner. A track 92 is atixed to the innerside of casing 4 directly over the line of extensions 9 and extends forthe full length of the extensions. top Iof extension 9a at a pluralityof points. These hangers are of T-shaped cross section and the top ofthe T is supported in the track 94. y This connection positions theextensions radially but permits axial movement. Other extensions arelinked to each other at the same number of points. Two tabs 96 dependfrom one extension and a single tab 98 extends from the adjacentextension to a position between the two tabs 96. A pin 100 passesthrough all three tabs to provide the link. This linkage is providedbetween all extensions 9. The extensions 20 are mounted in exactly thesame manner as extensions 9. i However, the track 92 is axed to theinner side of casing 4 directly under the line of extensions 20.

Operation In this cross flow heat exchanger, when in operation, onefluid is owing through the main ow duct or chamber 2 and another iluidis flowing through the header system 3. The flow through the fluidheader system 3 enters the flow duct or chamber 2 through the main inletheader 7. This iluid then passes to its inlet header extensions 9athrough 9]c by way of the inlet header adapters 10a through 10c. The uidthen passes from each inlet header extension to an outlet headerextension by Way of a plurality of Huid ow tubes 40. The outlet headerextensions 20 discharge into a main outlet header 12 by way of mainoutlet header adapters 22a through 22e. This fluid may be directed intothe main inlet header 7 by any means desired and it may be directed fromthe main outlet header 12 in any manner desired.

In the event of a leak in any of the uid flow tubes 40, any of the fluidso escaping would pass into a leak detection duct 62 and be carried toone of the collection tubes 80. From here the lluid will pass to acollector tube 86 and be directed to a leak detection and receiver means90.

The ow through the main ow duct or chamber 2 enters at its forward endand passes over the shells 64a through 64), hns 102, inlet and outletheader extensions 9a through 9j and 20a through 20f, the inlet andoutlet headers 7 and 12, and all adapters. The ow is discharged :fromthe duct or chamber 2 at its rearward end into a duct member 6. Asmentioned heinbefore, the chamber 2 is mounted for expansion within duct6, and the extensions 9 and 20 are mounted for expansion within thechamber 2.

It is to be understood that the invention is not limited to the speciiicembodiment herein illustrated and described, but may be used in otherways without departure from its spirit as defined by the followingclaims.

I claim:

l. In combination, a uid llow chamber, said chamber having an inlet endand an outlet end, a main inlet header extending into said chamberadjacent one end, a plurality of inlet header extensions extendinglengthwise in said chamber, said inlet header extensions being connectedto said main inlet header, a main outlet header extending into saidchamber adjacent one end, a plurality of outlet header extensionsextending lengthwise in said chamber, said outlet header extensionsbeing connected to said main outlet header, each inlet header extensionhaving a plurality of inlet header extension adapters iixed along itslength, said inlet adapters presenting a plurality of pipes extendingalong a line on each side of each inlet header extension, each outletheader extension having a plurality of outlet header extension adaptersfixed along its length,

` said outlet adapters presenting a plurality of pipes extendingyalong aline on each side of each outlet header extenfsion, the pipes in a lineon one side of each inlet header Hangers 94 are affixed to the assenteextension being connected to the pipes in a line on one side of eachoutlet header extension by an arcuate bank of tubes, each arcuate bankof tubes having its tubes therein arranged so that each successive tubeabuts the preceding tube, means providing a face along each side of eachline of inlet and outlet header extension adapters extending betweeneach of the pipes, a shell aflixed to each side of each bank of tubes,each shell extending along its arcuate length 4from a face on one sideof a line of cooperating inlet header extension adapters to a face onone side of a line of cooperating outlet header extension adapters, anarcuate space being formed between each adjacent tube in an arcuatebank, the portions of the face extending between each of the pipes ateach end and a shell, a collection tube extending along each side ofeach line of inlet and outlet header extension adapters, an arcuate ductlocated in each arcuate space extending from the face at one end to theface at the other end, passageways connecting each collection tube toall the ends of the arcuate ducts located in a line on the same side ofan inlet or outlet header extension adapter that the collection tube islocated.

2. In combination, a tiuid flow chamber, said chamber having an inletend and an outlet end, a main inlet header extending into said chamberadjacent one end, a plurality of inlet header extensions extendinglengthwise in said chamber, said inlet header extensions being connectedto said main inlet header, a main outlet header extending into saidchamber adjacent one end, a plurality of outlet header extensionsextending lengthwise in said chamber, said outlet header extensionsbeing connected to said main outlet header, each inlet header extensionhaving a plurality of inlet header extension adapters fixed along itslength, said inlet adapters presenting a plurality of pipes extendingalong a line on each side of each inlet header extension, each outletheader extension having a plurality of outlet header extension adaptersfixed along its length, said outlet .adapters presenting a plurality ofpipes extending along a line on each side of each outlet headerextension, the pipes in a line on one side of each inlet headerextension being connected to the pipes in a line on one side of eachoutlet header extension by an arcuate bank of tubes, each arcuate bankof tubes having its tubes therein arranged so that each successive tubeabuts the preceding tube, means providing a face along each side of eachline of inlet and outlet header extension adapters extending betweeneach of the pipes, a shell afiixed to each side of each bank of tubes,each shell extending along its arcuate length from a face on one side ofa line of cooperating in'let header extension adapters to a face -on oneside of a line of cooperating outlet header extension adapters, anarcuate space being formed between each adjacent tube in an arcuatebank, the portions of the face extending between each of the pipes ateach end and a shell, said means for providing a face also providing agroove along each side of each line of inlet and outlet header extensionadapters, a collection tube mounted along each groove, an arcuate ductlocated in each arcuate space extending from the face at one end to theface at the other end, passageways connecting each collection tube toall the ends of the arcuate ducts located in a line on the same side ofan inlet or outlet header extension adapter that the collection tube islocated.

l 3. In a combination, a fluid flow chamber, said chamber having aninlet end and an outlet end, a main inlet header extending into saidchamber adjacent one end, a plurality of inlet header extensionsextending lengthwise in said chamber, said inlet header extensions beingconnected to said main inlet header, a main outlet header extending intosaid chamber adjacent one end, a plurality of outlet header extensionsextending lengthwise in said chamber, said outlet header extensionsbeing connected to said main outlet header, each inlet header extensionhaving ,a plurality of Iinlet header extension adapters xed alongitslength, said inlet adapters presenting a plurality of pipes .extendingalong a line on ,each side of each inlet header extension, each outletheader extension having a plurality of outlet header extension adaptersfixed along -its length, said outlet adapters'presenting a plurality ofpipes `extending along a line on each side of each outlet headerextension, the ,pipes ,in a line on one `side of each inlet headerextension being connected to the pipes in a line on one side of eachOutlet header extension by an arcuate bank of tubes, each arcuate bankof tubes having its tubes therein arranged so that each successive tubeabuts lthe preceding tube, means providing fa vface along each side ofeach line of inlet and outlet header of extension adapters extendingbetween each of the pipes, a shell affixed to each side of each bank oftubes, each' shell extending along its arcuate length `from aface on oneside of alinecooperating inlet header extension adapters to a face 'on.one side of a line of cooperating outlet header yextension adapters, anarcuate space being formed between each adjacent tube in an arcuatebank, the portions of the face extending betweenzeach of the pipes`atveach endfand the shell, a collection tube extending along each sideof each line kof inlet and outlet header extensionadapters, an arcuateduct located in each arcuate space extending from the face at one end tothe face at the otherend, passageways connecting each collection tube toall the ends of the arcuate ducts located in a line on the same side ofan inlet or outlet header extension adapter that the collection tube islocated, said passageways each passing through the adjacent meansproviding a :face along each side of each line of inlet and outletheader extension adapters.

4. In combination, a fluid ow chamber, said chamber having an inlet endand an outlet end, a main inlet header extending into said chamberadjacent one end, a plurality of inlet header extensions extendinglengthwise in said chamber, said inlet header extensions being connectedto said main inlet header, a main outlet header extending into saidchamber adjacent one end, a plurality of outlet header extensionsextending lengthwise in said chamber, said outlet header extensionsbeing connected to said main outlet header, each inlet header extensionhaving a plurality of inlet header extension adapters xed along itslength, said inlet adapters presenting a plurality of pipes extendingalong a line on each side of each inlet header extension, eachoutletheader extension having a plurality of outlet header extension adaptersfixed along its length, said outlet adapters prer senting a plurality ofpipes yextending along a line on each side of each outlet headerextension, the pipes in a line on one sideof each inlet header extensionbeing connected to the pipes in a line onone side of each outlet headerextension by an arcuate bank of tubes, each arcuate bank of tubes havingits tubes therein arranged so that each successive tube abuts thepreceding tube, means providing a face along veach side of each line ofinlet and outlet header extension adapters extending between each of thepipes, a shell aiiixed to each side of each bank of tubes, each shellextending along its arcuate length from a face on one side of a line ofcooperating inlet header extension adapters to a face on one side of aline of cooperating outlet header extension adapters, an arcuate spacebeing formed between each adjacent tube in an arcuate bank, the portionsof the face extending between each of the pipes at each end and theshell, a collection tube extending along each side of eachline of inletand outlet header extension adapters, an arcuate duct located in eacharcuate space extending from the face at one end to the face at theother end, passageways connecting each collection tube to all the endsof the arcuate ducts located in aline on the same side of an inlet oroutlet header extension radapter that the collection tube `is locat ed,a .means vfor receiving and detecting a Huid, the free ends of eachAcollection tube being connected to said means.

5. In combination, a uid flow chamber, said *chamber having 1an inletend and an outlet `end, a `main inlet header extending into said chamberadjacent one end, a plurality-of inlet header extensions extendinglengthwise insaid chamber, -said inlet header extensions being connectedto said main inlet header, a main .outlet header extending into saidvchamber adjacent one end, a plurality -of outlet ,header extensionsextending lengthwise in said chamber, said-outlet header extensionsbeing connected to said .main `outlet header, each inlet headerextension having a plurality of inlet header extension adapters iixedalong its length, said inlet adapterspresenting a pluralityofpipesextending along aline on each side of each inlet headerextension, each outlet header extension having a plurality of outletheader extension adapters xed along its length, said outlet adapterspresenting a plurality of pipes extending along a line on each side-.ofeach outlet header extension, the pipes in a line on one side of eachinlet 'header extension beingtconnected to the pipes in a line on yoneside of each outlet header extension by an arcuate bank of tubes, eacharcuate bank of tubes having its tubes therein arranged so that eachsuccessive tube abuts the `preceding tube, means providing a-face alongeach side of each line of inlet and outlet header extension adaptersextending between each of the pipes, a shell aixed to each side of eachbank of tubes, each shell extending along its arcuate length from a faceon one side of a line of cooperating inletheader extension adapters to aface on one side of a line of cooperating outlet header extensionadapters, an arcuate space being formed between each adjacent tube in`an arcuate bank, the portions of the face extending between each of thepipes at each end and the shell, a collection tube extending along eachside of each line of inlet and outlet header extension adapters, anarcuate duct located in each arcuate space extending from the face atone end to theface at the other end, each arcuate duct containingmetallic bers, passageways connecting each collection tube to all theends of the arcuate ducts located in a line-on the same side of an inletor outlet header extension adapter that the collection tube is located.

`6. In combination, a uid ilow chamber, said chamber having an inlet endand an outlet end, a main inlet header extending into said chamberadjacent one end, a plurality of inlet header extensions extendinglengthwise in said chamber, said inlet header extensions being connectedto said main inlet header, a main outlet header extending into saidchamber adjacent one end, a plurality of outlet header extensionsextending lengthwise in said chamber, said outlet header extensionsbeingconnected to said main outlet header, each inlet header extensionhaving a plurality of inlet header extension adapters xed along itslength, said inlet adapters presenting a plurality of pipes extendingalong a line on each side of each inlet header extension, each outletheader extension having a plurality of outlet header extension adaptersxed along its length, said outlet adapters presenting a plurality ofpipes extending along a line on each side of each outlet headerextension, the pipes in a line on one side of each inlet headerextension being connected to the pipes in a line on one side of eachoutlet headerextension by an arcuate bank of tubes, each arcuate bankoftubes having its tubes therein arranged so that each successivetubeabuts the preceding tube, means providing a face along each side ofeach line of inlet and outlet header extension adapters extendingbetween each of the pipes, a shell ahxed to each side of each bankoftubes and extending from said inletend to said outlet end of4 saidchamber, each shell extending along its arcuate ,length froma faceon oneside of a line of cooperating inlet header extension adapters to a faceon one Aside of a' line of cooperating outlet header extension adapters,an

arcuate space being formed between each pair of adjacent tubes in anarcuate bank, the portions of the face extending between each of thepipes at each end and a shell, means for detecting a leak from a tubeinto one of said arcuate spaces.

7. In combination, a iluid flow chamber, said chamber having an inletend and an outlet end, a main inlet header extending into said chamberadjacent one end, an inlet header extension extending lengthwise in saidchamber, said inlet header extensions being connected to said main inletheader, a main outlet header extending into said chamber adjacent oneend, an outlet header extension extending7 lengthwise in said chamber,said outlet header extension being connected to said main outlet header,said inlet header extension being connected to said outlet headerextension by a bank of tubes, a shell axed to one side of said bank oftubes, face means 1ocated at each end of said bank of tubes, a spacebeing formed between a pair of tubes in said bank, the shell coveringone side of said bank and the face means at each end of the pair oftubes, means connected to said space for detecting a fluid leak intosaid space.

8. In combination, a fluid flow chamber, said chamber having an inletend and an outlet end, a main inlet header extending into said chamberadjacent one end, an inlet header extension extending lengthwise in saidchamber, said inlet header extensions being connected to said main inletheader, a main outlet header extending into said chamber adjacent oneend, an outlet header extension extending lengthwise in said chamber,said outlet header extension being connected to said main outlet header,said inlet header extension being connected to said outlet headerextension by a bank of tubes, a shell axed to one side of said bank oftubes, face means 1ocated at each end of said bank of tubes, a spacebeing formed between a pair of tubes in said bank, the shell coveringone side of said bank and the face means at each end of the pair oftubes, means connected to said space for detecting a fluid leak intosaid space, metallic fibers being contained in said space to provide foruid 10 ow through said space and heat transfer across said space fromthe tubes to the shell.

9. In combination, a cyindrical fluid ow chamber having an inlet end andan outlet end, a main inlet header extending radially into said chamberadjacent one end thereof, a plurality of inlet header extensions lyingin the radial plane including said inlet header and extending lengthwiseof said chamber from the inlet end to the outlet end thereof, said inletheader extensions being connected to said inlet header at spaced pointsalong the length thereof, a main outlet header extending radially intosaid chamber adjacent said one end thereof, a plurality of outlet headerextensions lying in the radial plane including said outlet header andextending lengthwise of said chamber from the inlet to the outlet endthereof, said outlet header extensions being connected to said outletheader at spaced points along the length thereof, each inlet headerextension having a plurality of inlet header extension adapters fixedalong its length presenting a plurality of pipes extending along a lineon each side of each inlet header extension, each outlet headerextension having a plurality of outlet header extension adapters fixedalong its length presenting a plurality of pipes eX- tending along aline on each side of each outlet header extension, the pipes in a lineon the same side of each inlet header extension being connected to thepipes in a line on the corresponding side of each outlet header eXtension by an arcuate bank of tubes.

References Cited in the le of this patent UNITED STATES PATENTS1,238,053 Smoot Aug. 21, 1917 1,908,733 Creel May 16, 1933 2,093,825Bach Sept. 21, 1937 2,187,470 Collins Jan. 16, 1940 2,187,555 FlindtIan. 16, 1940 FOREIGN PATENTS 557,583 France May 8, 1923 828,108 FranceMay 11, 1938

